Fetal Head Growth and Head Circumference at Birth in Children of Women with Psychotic Disorders and Population-Based Controls

Background Children of parents with psychotic disorders have a ˃50% increased risk to develop mental health problems, and over 30% have developed severe mental illness by early adulthood. Aberrant brain development may underly this familial risk. We aimed to investigate differences in brain development, reflected in fetal head circumference (HC) growth trajectories and HC at birth, between children of women with psychotic disorders and population-based controls. Study Design We collected fetal ultrasonography assessments at 20, 30, and 36 weeks of gestational age (GA) from medical records of N = 140 pregnant women having a psychotic disorder diagnosis and their N = 168 children. In the Generation R study, ultrasonography assessments were performed in the first, second, and/or third trimester in N = 8605 pregnant women and their children. In both groups, HC at birth was measured with measuring tape. Study Results Using generalized additive mixed modeling, we observed decreased non-linear fetal HC growth for offspring of women with psychotic disorders vs. controls from 30.7 weeks GA onwards. At birth, no significant difference was observed (b = 0.22, 95% CI [–0.133 to 0.573]), although offspring exposed to maternal psychosis showed more obstetric complications and suboptimal birth outcomes, including lower birthweight (b = –136.1, 95% CI [–229.0 to –43.2]). Conclusions This study showed decreased fetal head growth during the third trimester and lower birthweight in children of women with psychotic disorders. Together, these findings highlight potential relevance of altered fetal head growth for later neurodevelopmental outcomes and provide directions for possible underlying mechanisms of risk transmission in psychosis.